This device is installed between the neutral point of the primary winding (Y₀ connection) and ground of 6-35kV voltage transformers (hereinafter referred to as PTs). It functions as a nonlinear resistor harmonic damping component specifically designed for neutral point. High voltage filter capacitor devices are key solutions for improving harmonic suppression in 6kV, 10kV, and 35kV networks, ensuring stable operation, voltage quality, and reliable power delivery. High Voltage (HV) reactive power compensation and harmonic filtering solutions help customers to improve the performance of installations through energy savings and better power quality, enabling end users to save money and reduce the environmental impact of their operations. This overvoltage can occur when the busbar is unloaded or has few outgoing lines due to reasons such as. This article introduces a case of 35kV ring main unit busbar insulation breakdown failure, analyzes the failure causes and proposes solutions, providing reference for the construction and operation of new energy power stations. 1 Accident Overview On March 17, 2023, a photovoltaic. In the process of supervision and inspection of Jiangxi power grid, there are some phenomena in 35kV Xin'an substation, such as abnormal sound from transformer and capacitor, and overheating in capacitor. The bus and capacitor power quality test found serious harmonic exceeding.